Philadelphia Eagles‘ defensive coordinator Juan Castillo was under fire most of the 2011 season. Many times, it was for good reason. Under the guidance of head coach Andy Reid, the Eagles promoted Juan Castillo from offensive line coach to defensive coordinator. In the NFL, the move was unprecedented.

The Eagles defense struggled the first half of the 2011 season. They allowed 178 points in their first eight games. The NFL lock out shortened training camps, so players had less time to mesh. Evidently, the Eagles new defensive personnel (corner-backs Nnamdi Asomugha, Dominique Rodgers-Cromartie and defensive end Jason Babin), along with the addition of defensive line coach Jim Washburn, did not have enough time together.

The corner-backs were placed out of position in a new scheme. The defensive line installed a wide nine technique that created huge gaps the young, inexperienced linebackers could not fill. It was a mess.

The defense strengthened it’s play during the last half of the season. The Eagles went on to win their last four games, allowing only 46 points during the span (11.5 points per game). Overall, the 2011 defensive season numbers were surprising.

The NFL ranks defenses based on yardage allowed. This is a weak metric considering many NFL teams play a “bend but do not break” defense. The Eagles defense allowed a combined 324.9 yards per game, ranking them eighth in the entire NFL. I found that shocking considering the team finished 8-8, missing the playoffs. To put that in perspective, the Super Bowl Champion New York Giants finished 27th, allowing 376.4 yards per game.

I believe a better statistic for measuring a solid defense is points allowed. The Eagles defense finished tenth overall in 2011, allowing 20.5 points per game. Again, to put that in perspective, the Lombardi Trophy winning New York Giants finished 25th overall, allowing 25 points per game.

Juan Castillo must improve in his second season. Castillo must use the experience he gained to avoid the mistakes he made. Despite the season ending numbers, Castillo will always have to prove himself as to why he ascended to the position. Castillo’s position might be the hot seat in 2012, even more so than head coach Andy Reid.